Method and system for treating a dielectric film

ABSTRACT

A method and system for treating a dielectric film includes exposing at least one surface of the dielectric film to an alkyl silane, an alkoxysilane, an alkyl siloxane, an alkoxysiloxane, an aryl silane, an acyl silane, a cyclo siloxane, a polysilsesquioxane (PSS), an aryl siloxane, an acyl siloxane, or a halo siloxane, or any combination thereof. The dielectric film can include a low dielectric constant film with or without pores having an etch feature formed therein following dry etch processing. As a result of the etch processing or ashing, exposed surfaces in the feature formed in the dielectric film can become damaged, or activated, leading to retention of contaminants, absorption of moisture, increase in dielectric constant, etc. Damaged surfaces, such as these, are treated by performing at least one of healing these surfaces to, for example, restore the dielectric constant (i.e., decrease the dielectric constant) and cleaning these surfaces to remove contaminants, moisture, or residue. Moreover, preparation for barrier layer and metallization of features in the film may include treating by performing sealing of sidewall surfaces of the feature to close exposed pores and provide a surface for barrier film deposition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to co-pending U.S. patent application Ser.No. 10/682,196, entitled “Method and system for treating a dielectricfilm”, Attorney docket no. 243414US, filed on Oct. 10, 2003, the contentof which is incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and system for treating adielectric film and, more particularly, to a method and system oftreating a dielectric film in order to perform at least one of healing,sealing, and cleaning the dielectric film.

2. Description of Related Art

As is known to those in the semiconductor art, interconnect delay is amajor limiting factor in the drive to improve the speed and performanceof integrated circuits (IC). One way to minimize interconnect delay isto reduce interconnect capacitance by using low dielectric constant(low-k) materials during production of the IC. Such low-k materials havealso proven useful for low temperature processing. Thus, in recentyears, low-k materials have been developed to replace relatively highdielectric constant insulating materials, such as silicon dioxide. Inparticular, low-k films are being utilized for inter-level andintra-level dielectric layers between metal layers of semiconductordevices. Additionally, in order to further reduce the dielectricconstant of insulating materials, material films are formed with pores,i.e., porous low-k dielectric films. Such low-k films can be depositedby a spin-on dielectric (SOD) method similar to the application ofphoto-resist, or by chemical vapor deposition (CVD). Thus, the use oflow-k materials is readily adaptable to existing semiconductormanufacturing processes.

While low-k materials are promising for fabrication of semiconductorcircuits, the present inventors have recognized that these films alsoprovide many challenges. First, low-k films tend to be less robust thanmore traditional dielectric layers and can be damaged during waferprocessing, such as by etch and plasma ashing processes generally usedin patterning the dielectric layer. Further, some low-k films tend to behighly reactive when damaged, particularly after patterning, therebyallowing the low-k material to absorb water and/or react with othervapors and/or process contaminants that can alter the electricalproperties of the dielectric layer.

Moreover, the present inventors have recognized that the porosity ofsome low-k dielectric films often exacerbates the problems ofintegrating metallization with the dielectric. In general, theintegration of copper metallization with low-k dielectric films requiresthe use of a damascene structure, wherein metal wiring patterns areformed within the dielectric film prior to copper deposition. In orderto minimize the diffusion of copper into the dielectric film, a barrierlayer is typically formed on the internal surfaces of these patternsfollowing pattern etching. However, exposure of the pores and/or damageof the low-k film following the etching of patterns in the dielectricfilm causes problems with diffusion of the barrier material and copperthrough imperfections in the barrier film local to these exposed pores,as well as poor adhesion of the barrier layer to the dielectric film.

Additionally, porous low-k dielectric films, such as the damaged low-kfilms noted above, are susceptible to absorbing moisture, and othercontaminants. For example, following pattern etching, the exposedsurfaces can change from being hydrophobic to becoming hydrophilic, theexposed surface layer can become depleted of carbon (C), and the porescan retain contaminants from the etch process.

SUMMARY OF THE INVENTION

One aspect of the present invention is to reduce or eliminate any of theabove-described problems or other problems in the prior art relating toprocessing dielectric films.

Another aspect of the present invention is to treat a dielectric film inorder to heal, seal and/or clean the dielectric film.

Yet another aspect of the present invention is to treat a dielectricfilm in order to reduce diffusion of barrier material into thedielectric film and/or improve adhesion of the barrier film to thedielectric film.

Any of these and/or other aspects may be provided by a method oftreating a dielectric film in accordance with the present invention. Inone embodiment, the method includes exposing at least one surface of thedielectric film to a treating compound including an alkyl silane, analkoxysilane, an alkyl siloxane, an alkoxysiloxane, an aryl silane, anacyl silane, a cyclo siloxane, a polysilsesquioxane (PSS), an arylsiloxane, an acyl siloxane, or a halo siloxane, or any combinationthereof, wherein: the dielectric film has a dielectric constant valueless than the dielectric constant of SiO₂.

In another embodiment, a processing system for treating a dielectricfilm on a substrate is described including: a process chamber; a fluiddistribution system coupled to said process chamber and configured tosupply a treating compound to said process chamber in order to treatsaid dielectric film on said substrate, said treating compound comprisesan alkyl silane, an alkoxysilane, an alkyl siloxane, an alkoxysiloxane,an aryl silane, an acyl silane, a cyclo siloxane, a polysilsesquioxane(PSS), an aryl siloxane, an acyl siloxane, or a halo siloxane, or anycombination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1A through 1E present a simplified schematic representation of amethod of forming and treating a dielectric film in accordance with anembodiment of the present invention;

FIG. 2 presents a method of producing a dielectric film according to anembodiment of the present invention;

FIGS. 3A and 3B illustrate a method of treating a dielectric film;

FIGS. 4A through 4C show schematic representations of organosiliconstructures used as for treating a dielectric film according to anembodiment of the present invention;

FIG. 4D shows a schematic representation of reactions with a silanolgroup in a dielectric material according to another embodiment of thepresent invention;

FIG. 4E illustrates steric hindrance between a silanol group and a silylgroup on a surface of a dielectric material;

FIG. 5 presents a processing system for treating a dielectric filmaccording to an embodiment of the present invention;

FIG. 6 presents a simplified schematic of a supercritical processingsystem according to another embodiment of the present invention;

FIG. 7 presents a detailed schematic diagram of a supercriticalprocessing system according to another embodiment of the presentinvention;

FIG. 8 is a plot of pressure versus time for supercritical cleaning,rinsing, or curing step according to an embodiment of the presentinvention;

FIG. 9 is a schematic block diagram outlining steps for treating adielectric layer according to another embodiment of the presentinvention; and

FIGS. 10A and 10B show infrared absorption spectra for a silicon-basedlow-k dielectric material before and after treatment with a healingcompound.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views, FIGS. 1Athrough 1E present a schematic representation of a method of forming apattern in a dielectric film and treating the exposed surfaces of theetched pattern in the dielectric film in order to perform at least oneof healing, sealing, and cleaning these surfaces. Additionally, FIG. 2presents a flow chart 100 of performing the method according to anembodiment of the present invention. As shown in FIGS. 1A, 1B, and 2, adielectric film 20 is formed in 110 on an upper surface of a substrate10 that may or may not include additional layers. The substrate 10 maybe a semiconductor, a metallic conductor, or any other substrate towhich the dielectric film is to be formed upon. The dielectric film hasa nominal dielectric constant value less than the dielectric constant ofSiO₂, which is approximately 4 (e.g., the dielectric constant forthermal silicon dioxide can range from 3.8 to 3.9). More specifically,the dielectric film 20 may have a dielectric constant of less than 3.0,or a dielectric constant ranging from 1.6 to 2.7.

The dielectric film 20 can be formed using chemical vapor deposition(CVD) techniques, or spin-on dielectric (SOD) techniques such as thoseoffered in the Clean Track ACT 8 SOD and ACT 12 SOD coating systemscommercially available from Tokyo Electron Limited (TEL). The CleanTrack ACT 8 (200 mm) and ACT 12 (300 mm) coating systems provide coat,bake, and cure tools for SOD materials. The track system can beconfigured for processing substrate sizes of 100 mm, 200 mm, 300 mm, andgreater. Other systems and methods for forming a dielectric film on asubstrate are well known to those skilled in the art of both spin-ondielectric technology and CVD dielectric technology.

The dielectric film 20 can, for example, be characterized as a lowdielectric constant (or low-k) dielectric film. The dielectric film 20may include at least one of an organic, inorganic, and inorganic-organichybrid material. Additionally, the dielectric film 20 may be porous ornon-porous. For example, the dielectric film may include an inorganic,silicate-based material, such as oxidized organosilane (or organosiloxane), deposited using CVD techniques. Examples of such filmsinclude Black Diamond™ CVD organosilicate glass (OSG) films commerciallyavailable from Applied Materials, Inc., or Coral™ CVD films commerciallyavailable from Novellus Systems. Additionally, for example, porousdielectric films can include single-phase materials, such as a siliconoxide-based matrix having CH₃ bonds that are broken during a curingprocess to create small voids (or pores). Additionally, for example,porous dielectric films can include dual-phase materials, such as asilicon oxide-based matrix having pores of organic material (e.g.,porogen) that is evaporated during a curing process. Alternatively, thedielectric film 20 may include an inorganic, silicate-based material,such as hydrogen silsesquioxane (HSQ) or methyl silsesquioxane (MSQ),deposited using SOD techniques. Examples of such films include FOx HSQcommercially available from Dow Corning, XLK porous HSQ commerciallyavailable from Dow Corning, and JSR LKD-5109 commercially available fromJSR Microelectronics. Still alternatively, the dielectric film 20 caninclude an organic material deposited using SOD techniques. Examples ofsuch films include SiLK-I, SiLK-J, SiLK-H, SiLK-D, and porous SiLKsemiconductor dielectric resins commercially available from DowChemical, and FLARE™, and Nano-glass commercially available fromHoneywell.

Once the dielectric film 20 is prepared, a patterned mask 30 is formedin 120 on an upper surface thereof. The patterned mask 30 can include apattern 35 formed in a layer of light-sensitive material, such asphotoresist, using micro-lithography, followed by the removal of theirradiated regions of the light-sensitive material (as in the case ofpositive photoresist), or non-irradiated regions (as in the case ofnegative resist) using a developing solvent. Alternatively, the mask 30can include a bilayer mask, or multilayer mask, having ananti-reflective coating (ARC), such as a buried ARC (BARC) layer, asacrificial DUO™ layer, or a tunable etch resistant ARC (TERA) layer,embedded therein. For example, the mask layer (or layers) can be formedusing a track system, or CVD system. The track system can be configuredfor processing 248 nm resists, 193 nm resists, 157 nm resists, EUVresists, (top/bottom) anti-reflective coatings (TARC/BARC), and topcoats. For example, the track system can include a Clean Track ACT 8, orACT 12 resist coating and developing system commercially available fromTokyo Electron Limited (TEL). Other systems and methods for forming aphotoresist film on a substrate are well known to those skilled in theart of spin-on resist technology. Additionally, for example, the maskpattern can be formed using any suitable conventional steppinglithographic system, or scanning lithographic system.

The mask pattern 35 can be transferred to the underlying dielectric film20 in 130 to form feature 40 having sidewalls 45 using dry plasmaetching. For instance, when etching oxide dielectric films such assilicon oxide, silicon dioxide, etc., or when etching inorganic low-kdielectric films such as oxidized organosilanes, the etch gascomposition generally includes a fluorocarbon-based chemistry such as atleast one of C₄F₈, C₅F₈, C₃F₆, C₄F₆, CF₄, etc., and at least one of aninert gas, oxygen, and CO. Additionally, for example, when etchingorganic low-k dielectric films, the etch gas composition generallyincludes at least one of a nitrogen-containing gas, and ahydrogen-containing gas. The techniques for selectively etching adielectric film, such as those described earlier, are well known tothose skilled in the art of dielectric etch processes.

During etching, exposed surfaces within the feature formed in thedielectric film 20, such as sidewalls 45, can be damaged, or activated.The damage or activation incurred by these surfaces can lead to theabsorption of water, or the adhesion of contaminants and/or chemicalsduring etch processing (i.e., dry etching, or mask removal duringashing). For example, porous low-k dielectric films can be verysusceptible to damage and/or activation during etch processing. Ingeneral, porous low-k films are most commonly silicon-oxide based withsilanol (Si—OH) groups and/or organo groups. These materials can becomeactivated or damaged due in part to the depletion of an organiccomponent during etch processing. In either case, additional silanolgroups are exposed which can readily absorb water, and/or othercontaminants. Accordingly, device structures with exposed low-kdielectric layers are difficult to handle and maintain contaminant free,especially after patterning steps. Moreover, activation and/or damage tothe bulk of the low-k material can result in an increase to thedielectric constant (k-value). It has been observed that the activatedor damaged low-k film can exhibit an increase of the k-value by a valueof one or more.

As described earlier, in an embodiment of the present invention, thedamaged, exposed surfaces (following, for example, an etch, or ashprocess) are treated to perform at least one of healing, sealing, andcleaning of these damaged surfaces. The healing of a damaged surfaceincludes restoring the value of the dielectric constant.

Therefore, according to an embodiment of the present invention, thedielectric film 20 is treated in 140 in order to perform at least one ofhealing damaged surfaces, sealing exposed porous surfaces, and cleaningdamaged surfaces, such as sidewalls 45, as shown in FIG. 1E. The healingprocess includes the rejuvenation of the dielectric film by restoringthe value of the dielectric constant. The restoration of the k-valuecan, for example, be characterized by replenishing carbon depleted siteswith carbon-containing material (e.g., CH₃). The healing process mayalso include passivation of the low-k surface using a treating agentthat attacks the silanol (Si—OH) groups on the surface to the low-k filmto form surface capped silyl groups that passivate the surface. Detailsof passivating the low-k surface are provided in the U.S patentapplication titled METHOD OF PASSIVATING OF LOW DIELECTRIC MATERIALS INWAFER PROCESSING, Attorney Docket No. SSI-03501 filed Mar. 4, 2003, theentire content of which is incorporated herein by reference.Additionally, the sealing process can, for example, be characterized bythe sealing of exposed pores in exposed surfaces. Furthermore, thecleaning process can include any one of removing moisture, removingcontaminants or residue, etc.

During this treating process, the dielectric film 20 is exposed to atreating compound including a C_(x)H_(y)-containing compound, whereinthe subscripts “x” and “y” represent integers greater than or equal tounity. Alternately, the treating compound can further include at leastone of a nitrogen (N)-containing and a chlorine (Cl)-containing compoundin order to assist the surface chemistry on dielectric film 20. Forexample, the C_(x)H_(y)-containing component can include at least one ofa CH-containing, CH₂-containing, and a CH₃-containing compound.

FIGS. 3A and 3B further illustrate an example of the treating process.In FIG. 3A, a porous low-k dielectric film 142 is shown having pores144, wherein, following an etching or ashing process, it has beenobserved that exposed surfaces within these pores become damaged. Thesurface damage manifests as dangling bonds 146 that can absorb moisture(i.e., H₂O) as an OH site. Now referring to FIG. 3B, the dielectric filmis exposed to a treating compound including a C_(x)H_(y) containingmaterial (e.g., CH₃) during which the treating process facilitatescleaning pores 144 to remove OH and other residue, healing the exposedsurfaces of the pores by replacing the OH and dangling bonds 146 withC_(x)H_(y) (e.g., CH₃), and sealing pores 144 by the adhesion ofC_(x)H_(y) (e.g., CH₃) containing molecules 148 onto the dielectric film142 to close the exposed pores 144. Thus, the treated low-k filmincludes a surface region having C_(x)H_(y) material that provides thelow-k film with improved physical properties such as free fromcontamination and moisture, fewer dangling bonds, or sealed pores in thesurface region. Further the C_(x)H_(y) material in the surface regionprovides a dielectric constant lower than corresponding film without theC_(x)H_(y) material.

Referring now to FIG. 4A, the treating compound includes a silanestructure 150 which can have all organo groups, such as in the case withhexamethyldisilizane (HMDS), or a combination of organo and halidegroups (F, Cl, Br, etc.), which are attached to any one of the positions1 to 4.

Now referring to FIG. 4B, the treating compound includes a pent-valentorganosilicon compound 152, wherein the silicon atom is coordinated to 5ligands in the positions 1, 2, 3, 4, and 5 in a tiganolbipyramidalconfiguration. Typically, such compounds 152 are anions with one or moreof the positions 1-5 being coordinated with halide atom, such as in thecase with a difluorotrimethylilicate anion. When the structure 152 is ananion, the compound 152 also includes a suitable cation, such as sodium,potassium or any other inorganic or organic cation (not shown).

Now referring to FIG. 4C, the treating compound includes a silazanestructure 154, which can be described as an amine structure with twoorganosilyl groups coordinated to the nitrogen of the amine, such as inthe case of hexamethyldisilazane (HMDS).

FIG. 4D shows schematic representations of hexamethyldisilazane (HMDS)reacting with silanol groups on a surface of a dielectric material inreaction sequence (1) and trimethyldisilazane (TMDS) reacting withsilanol groups on a surface of the dielectric material in reactionsequence (2). Note that trimethyldisilazane (TMDS) is a product in thereaction sequence (1), which can then further react with silanol groupson a surface of the low-k material in accordance with reaction sequence(2). Hence, hexamethyldisilazane (HMDS) provides is an excellenttreating compound for use in accordance with the method of the presentinvention.

FIG. 4E illustrates steric hindrance between a silanol group 53 andsilyl-group 55 on a surface 51 of a dielectric material. Note that thesilanol group 53 is extremely large and can actually provide aprotective barrier for the silanol group 53. Accordingly, it is notgenerally possible to completely silylate an entire surface or bulk of adielectric material. However, when the dielectric material ispre-treated, it is believed that a greater percent of the silanol groups53 are replace with silyl-groups 55 on the surface 51.

Alternatively, the treating compound can include at least one ofhexamethyldisilazane (HMDS), trimethyldisilazane (TMDS),chlorotrimethylsilane (TMCS), trichloromethylsilane (TCMS),[C₆H₅Si(CH₃)₂]₂NH (or 1,3-Diphenyl-1,1,3,3-tetramethyldisilazane),C₁₅H₂₉NSi (orN-tert-Butyl-1,1-dimethyl-1-(2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl)-silanamine), (CH₃)₂NH Dimethylamine, H₂N(CH₂)₃Si(OC₂H₅)₃3-Aminopropyltriethoxysilane, (CH₄SiO)₄ (or TMCTS, ortetramethylcyclotetrasiloxane), and [(CH₃)₂SiO]₄ (or OMCTS, oroctamethylcyclotetrasiloxane).

In one example, when treating a porous low-k dielectric film with poresizes less than or equal to 1 nm, the treating compound can include atleast one of HMDS, TMDS, and (CH₃)₂NH Dimethylamine. In a secondexample, when treating a porous low-k dielectric film with pore sizesgreater than or equal to 1 nm, the treating compound can include atleast one of [C₆H₅Si(CH₃)₂]₂NH, C₁₅H₂₉NSi, and H₂N(CH₂)₃Si(OC₂H₅)₃3-Aminopropyltriethoxysilane. Alternatively, in a third example, adielectric film is exposed to a first treating compound, such as atleast one of HMDS, TMDS, and (CH₃)₂NH Dimethylamine, for a first periodof time, and exposed to a second treating compound, such as at least oneof [C₆H₅Si(CH₃)₂]₂NH, C₁₅H₂₉NSi, and H₂N(CH₂)₃Si(OC₂H₅)₃3-Aminopropyltriethoxysilane, for a second period of time.

Alternatively, the treating compound can include at least one of analkyl silane (also including alkoxysilanes), an alkyl siloxane (alsoincluding alkoxysiloxanes), an aryl silane, an acyl silane, a cyclosiloxane, a polysilsesquioxane (PSS), an aryl siloxane, an acylsiloxane, or a halo siloxane, or any combination thereof.

The alkyl silane can, for example, comprise:

-   hexamethyldisilazane (HMDS),-   tetramethyldisilazane (TMDS),-   trimethylsilyldimethylamine (TMSDMA),-   trimethylsilyldiethylamine (TMSDEA),-   N-trimethylsilyl-imidazole (TMSI),-   methyltrimethoxysilane (MTMOS),-   vinyltrimethoxysilane (VTMOS),-   trimethylchlorosilane (TMCS),-   dimethylsilyldimethylamine (DMSDMA),-   dimethylsilyidiethylamine (DMSDEA),-   bis(dimethylamino)methyl silane (B[DMA]MS),-   bis(dimethylamino)dimethyl silane (B[DMA]DS),-   dimethylaminopentamethyldisilane (DMAPMDS),-   dimethylaminodimethyldisilane (DMADMDS),-   disila-aza-cyclopentane (TDACP),-   disila-oza-cyclopentane (TDOCP),-   triethylchlorosilane (TECS),-   tetramethoxysilane (TMOS),-   dimethyldimethoxysilane (DMDMOS),-   tetraethoxysilane (TEOS),-   methyltriethoxysilane (MTEOS),-   dimethyldiethoxysilane (DMDEOS),-   vinyltriethoxysilane (VTEOS),-   trimethylmethoxysilane (TMMS),-   trimethylethoxysilane (TMES),-   trimethylsilanol (TMS-OH),-   bis(trimethoxysilyl)hexane,-   bis(trimethoxysilyl)octane,-   bis(trimethylsilylmethyl)dimethoxysilane,-   bistrimethoxysilylethane,-   cyclohexylmethyldimethoxysilane,-   cyclohexyltrimethoxysilane,-   dicyclopentyldimethoxysilane,-   diisobutyidimethoxysilane,-   diisopropyldimethoxysilane,-   dimethyldimethoxysilane,-   hexadecyltrimethoxysilane,-   octyldimethylmethoxysilane,-   trimethoxysilane,-   trimethylmethoxysilane,-   tris(dimethylsiloxy)ethoxysilane, or    any combination thereof.

The alkyl siloxane can, for example, comprise:

-   (3-glycidoxypropyl) pentamethyldisiloxane,-   1,1,1,3,3,5,5-heptamethyltrisiloxane,-   1,1,1,5,5,5-hexamethyltrisiloxane,-   1,1,3,3,5,5,7,7-octamethyltetrasiloxane,-   1,1,3,3,5,5-hexamethyltrisiloxane,-   1,1,3,3-tetracyclopentyldichlorodisiloxane,-   1,1,3,3-tetraethoxy-1,3-dimethyldisiloxane,-   1,1,3,3-tetraisopropyl-1,3-dichlorodisiloxane,-   1,1,3,3-tetraisopropyldisiloxane,-   1,1,3,3-tetramethyl-1,3-diethoxydisiloxane,-   1,1,3,3-tetramethyldisiloxane,-   1,3-bis(2-aminoethylaminomethyl)tetramethyldisiloxane,-   1,3-bis(3-aminopropyl)tetramethyldisiloxane,-   1,3-bis(chloromethyl)-1,1,3,3-tetrakis(trimethylsiloxy)disiloxane,-   1,3-bis(chloropropyl)tetramethyldisiloxane,-   1,3-bis(glycidoxypropyl)tetramethyldisiloxane,-   1,3-bis(hydroxybutyl)tetramethyldisiloxane,-   1,3-bis(hydroxypropyl)tetramethyldisiloxane,-   1,3-bis(trimethylsiloxy)-1,3-dimethyldisiloxane,-   1,3-diallyleterakis(trimethylsiloxy)disiloxane,-   1,3-diallyltetramethyldisiloxane,-   1,3-dichlorotetramethyldisiloxane,-   1,3-diethyltetramethyldisiloxane,-   1,3-diethynyltetramethyldisiloxane,-   1,3-dimethyltetramethoxydisiloxane,-   1,3-dioctyltetramethyldisiloxane,-   1,3-divinyl-1,3-dimethyl-1,3-dichlorodisiloxane,-   1,3-divinyltetraethoxydisiloxane,-   1,3-divinyltetramethyldisiloxane,-   1,5-dichlorohexamethyltrisiloxane,-   1,5-d ivinylhexamethyltrisiloxane,-   1,7-dichlorooctamethyltetrasiloxane,-   1-allyl-1,1,3,3-tetramethyldisiloxane,-   2-[methoxy(polyethyleneoxy)propyl]heptamethyltrisiloxane,-   3,5-bis(chloromethyl)octamethyltetrasiloxane,-   3-[hydroxy(polyethyleneoxy)propyl] heptamethyltrisiloxane,-   3-aminopropylpentamethyldisiloxane,-   3-chloromethylheptamethyltrisiloxane,-   3-octylheptamethyltrisiloxane,-   bis(3-chloroisobutyl)tetramethyldisiloxane,-   bis(chloromethyl)tetramethyldisiloxane,-   bis(cyanopropyl)tetramethyldisiloxane,-   bis(tridecafluoro-1,1,2,2-tetrahydrooctyl)tetramethyldisiloxane,-   bis(trifluoropropyl)tetramethyld isiloxane,-   bis[(biscycloheptenyl)ethyl]tetramethyldisiloxane,-   bis-2-[3,4-(epoxycylcohexyl)ethyl]tetramethyldisiloxane,-   chloromethylpentamethyld isiloxane,-   decamethylcyclopentasiloxane,-   decamethyltetrasiloxane,-   divinyletrakis(trimethylsiloxy)disiloxane,-   dodecamethylcyclohexasiloxane,-   dodecamethylpentasiloxane,-   hexaethyldisiloxane,-   hexamethyldisiloxane,-   hexavinyldisiloxane,-   octamethyltrisiloxane,-   pentamethyldisiloxane,-   tetradecamethylhexasiloxane, or    any combination thereof.

The aryl silane can, for example, comprise:

-   benzyltriethoxysilane,-   di(p-tolyl)dimethoxysilane,-   diphenyldiethoxysilane,-   diphenyldihydroxysilane,-   diphenyldimethoxysilane,-   diphenylmethylethoxysilane,-   p-bis(trimethoxysilylmethyl)benzene,-   phenyldimethylethoxysilane,-   t-butyld iphenyl methoxysilane,-   triphenylethoxysilane,-   triphenylsilanol,-   vinyidiphenylethoxysilane,-   dibenzyloxydiacetoxysilane,-   phenylacetoxytrimethylsilane,-   phenyldimethylacetoxysilane,-   phenyltriacetoxysilane, or    any combination thereof.

The acyl silane can, for example, comprise:

-   bistrimethylsilyl urea (BTSU),-   bis(trimethylsilyl)acetamide (BSA),-   bis(trimethylsilyl)trifluoromethylacetamide (BSTFA),-   triacetylvinylsilane (TAVS),-   N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA),-   N-methyl-N-tert-butyldimethylsilyl-trifluoroacetamide (MBDSTFA),-   N-methyl-N-trimethylsilyl-heptafluorobutyramide (MSHFBA),-   acetoxytrimethylsilane (TMAS),-   3-trifluoroacetoxypropyltrimethoxysilane,-   acetoxyethyldimethylchlorosilane,-   acetoxyethyl methyldichlorosilane,-   acetoxyethyltriclorosilane,-   acetoxyethyltriethoxysilane,-   acetoxyethyltrimethoxysilane,-   acetoxymethyldimethylacetoxysilane,-   acetoxymethyltriethoxysilane,-   acetoxymethyltrimethoxysilane,-   acetoxymethyltrimethylsilane,-   acetoxypropylmethyldichlorosilane,-   dimethyldiacetoxysilane,-   di-t-butyldiacetoxysilane,-   ethyltriacetoxysilane,-   methyltriacetoxysilane,-   tetraacetoxysilane,-   tetrakis(trifluoroacetoxy)silane,-   triethylacetoxysilane,-   vinylmethyldiacetoxysilane,-   vinyltriacetoxysilane,-   dibenzyloxydiacetoxysilane,-   phenylacetoxytrimethylsilane,-   phenyldimethylacetoxysilane,-   phenyltriacetoxysilane, or    any combination thereof.

The cyclo siloxane can, for example, comprise:

-   1,3,5,7-tetramethylcyclotetrasiloxane,-   heptamethylcyclotetrasiloxane,-   hexaethylcyclotrisiloxane,-   hexamethylcyclotrisiloxane,-   octamethylcyclotetrasiloxane,-   pentamethylcyclopentasiloxane,-   pentavinylpentamethylcyclopentasiloxane,-   tetraethylcyclotetrasiloxane,-   hexaphenylcyclotrisiloxane,-   octaphenylcyclotetrasiloxane,-   (acetoxyethyl)heptamethylcylcotetrasiloxane,-   tetrakis(diphenylphosphinoethyl)tetramethylcylcotetrasiloxane, or    any combination thereof.

The polysilsesquioxane (PSS) can, for example, comprise:

-   octamethyl silsesquioxane,-   decamethyl silsesquioxane,-   octavinyl silsesquioxane,-   decavinyl silsesquioxane,-   octamethoxy silsesquioxane,-   decamethoxy silsesquioxane,-   chloropropylisobutyl-PSS, or    any combination thereof.

The aryl siloxane can, for example, comprise:

-   1,1,3,3-tetraphenyldimethyldisiloxane,-   1,1,3,5,5-pentaphenyl-1,3,5-trimethyltrisiloxane,-   1,1,5,5-tetraphenyl-1,3,3,5-tetramethyltrisiloxane,-   1,3-dichloro-1,3-diphenyl-1,3-dimethyldisiloxane,-   1,3-dichlorotetraphenyldisiloxane,-   1,3-diphenyl-1,1,3,3-tetrakis(dimethylsiloxy)disiloxane,-   1,3-diphenyl-1,1,3,3-tetramethyldisiloxane,-   1,3-divinyl-1,3-diphenyl-1,3-dimethyldisiloxane,-   1,4-bis(trimethoxysilylethyl)benzene,-   1,5-bis(glycidoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane,-   1,5-divinyl-3,3-diphenyl-1,1,5,5-tetramethyltrisiloxane,-   1,5-d ivinyl-3-phenyl pentamethyltrisiloxane,-   3,5-diphenyloctamethyltetrasiloxane,-   3-phenyl-1,1,3,5,5-pentamethyltrisiloxane,-   3-phenylheptamethyltrisiloxane,-   bis(m-allylphenyldimethylsilyloctyl)-tetramethyldisiloxane,-   bis(pentafluorophenyldimethoxysilane,-   divinyltetraphenyldisiloxane,-   hexaphenyldisiloxane,-   hexaphenylcyclotrisiloxane,-   1,3-bis[acrylomethyl)phenethyl]tetramethyldisiloxane,-   octaphenylcyclotetrasiloxane,-   (acetoxyethyl)heptamethylcylcotetrasiloxane,-   tetrakis(diphenylphosphinoethyl)tetramethylcylcotetrasiloxane, or    any combination thereof.

The acyl siloxane can, for example, comprise:

-   1,1,1,3,3-pentamethyl-3-acetoxydisiloxane,-   1,3-bis(3-carboxypropyl)tetramethyldisiloxane,-   1,3-bis(3-methacryloxypropyl)tetrakis(trimethylsiloxy)disiloxane,-   1,3-bis(3-methacryloxypropyl)tetramethyldisiloxane,-   11-acetoxyu ndecyltrichlorosilane,-   2-[acetoxy(polyethyleneoxy)propyl]heptamethyltrisiloxane,-   methacryloxypropylpentamethyldisiloxane,-   1,3-bis[acrylomethyl)phenethyl]tetramethyldisiloxane, or    any combination thereof.

The halo siloxane can, for example, comprise:

-   hexachlorodisiloxane,-   octachlorotrisiloxane, or    any combination thereof.

Alternately, in addition to exposing the dielectric film to the treatingcompound, the substrate can be heated in order to assist, or accelerate,the surface reactions facilitated by the exposure. The substratetemperature can range from 50 C to 400 C, and desirably, the substratetemperature can range from 100 C to 200 C.

FIG. 5 presents a block diagram of a processing system 170 for treatingthe dielectric film in order to perform at least one of healing,sealing, and cleaning exposed surfaces in the dielectric film followingetch processing or ashing. Processing system 170 includes a processchamber 172, a fluid distribution system 174 coupled to the processchamber 172 and configured to introduce the treating compound to asubstrate mounted in process chamber 172, and a controller 176 coupledto the process chamber 172 and fluid distribution system 174, andconfigured to control the processing system 170 according to a processrecipe.

The processing system 170 can include a vapor-phase treatment apparatus,wherein the treating compound is introduced to the dielectric film viavapor transport with or without a carrier gas. For example, fluiddistribution system 174 can include a carrier gas supply system forsupplying a carrier gas, or inert gas such as nitrogen, and a reservoirof treating compound, such as a reservoir of HMDS. The fluiddistribution system 174 can further include a vapor delivery system thatpermits bubbling the carrier gas through the reservoir of treatingfluid, and transporting the treating compound vapor to a process chamber172 for exposure to a substrate having a dielectric film to be treated.Furthermore, the fluid distribution system 174 can further include atemperature control system for elevating the temperature of the vapordelivery system in order to prevent the condensation of treatingcompound vapor therein. The process chamber 172 can further include asubstrate holder for mounting the substrate that may be stationary,translatable, or rotatable. Additionally, the substrate holder can beconfigured to heat and/or control the temperature of the substrate inorder to assist the surface reactions upon exposure of the dielectricfilm to the treating compound. The substrate temperature can range from50 C to 400 C, and desirably, the substrate temperature can range from100 C to 200 C. For additional details, an exemplary vaportransport-supply apparatus is described in U.S. Pat. No. 5,035,200,assigned to Tokyo Electron Limited, which is incorporated herein byreference in its entirety.

The processing system 170 can include a liquid-phase treatmentapparatus, wherein the treating compound is introduced to the dielectricfilm via liquid transport with or without a carrier liquid. For example,the fluid distribution system 174 can include a reservoir of treatingcompound, such as a reservoir of HMDS, and a liquid delivery system forcirculating the treating compound through process chamber 172. Processchamber 172 can include an immersion bath having a substrate holder fortransporting the substrate, having a dielectric film to be treated, intoand out of the bath of treating compound. Additionally, the substrateholder can be configured to heat and/or control the temperature of thesubstrate in order to assist the surface reactions upon exposure of thedielectric film to the treating compound. The substrate temperature canrange from 50 C to 400 C, and desirably, the substrate temperature canrange from 100 C to 200 C. Bubbles can, for example, be generated withinthe bath of treating compound in order to create some agitation topromote chemical transport local to the treated surfaces on thesubstrate. For additional details, an exemplary immersion bath apparatusis described in U.S. Pat. No. 5,730,162, assigned to Tokyo ElectronLimited, and immersion bath apparatus with ultrasonic agitation isdescribed in U.S. Pat. No. 5,911,232, each of which are incorporatedherein by reference in their entirety. Additionally, for example, thefluid distribution system 174 can include a reservoir of treatingcompound, such as a reservoir of HMDS, and a liquid delivery system fordispensing the treating compound onto an upper surface of the substratehaving the dielectric film to be treated. The liquid delivery system canfurther include one or more fluid nozzles for dispensing the treatingcompound. The process chamber 172 can further include a substrate holderfor mounting the substrate that may be stationary, translatable, orrotatable. Additionally, the substrate holder can be configured to heatand/or control the temperature of the substrate in order to assist thesurface reactions upon exposure of the dielectric film to the treatingcompound. The substrate temperature can range from 50 C to 400 C, anddesirably, the substrate temperature can range from 10° C. to 200 C. Foradditional details, an exemplary liquid dispensing-supply apparatus isdescribed in U.S. Pat. No. 6,589,338, assigned to Tokyo ElectronLimited, which is incorporated herein by reference in its entirety.

The processing system 170 can include a supercritical processingapparatus, wherein the treating compound is introduced to the dielectricfilm via a supercritical fluid, such as supercritical carbon dioxide(SCCO₂), or liquid CO₂, to be described in greater detail below.

Controller 176 includes a microprocessor, memory, and a digital I/O port(potentially including D/A and/or A/D converters) capable of generatingcontrol voltages sufficient to communicate and activate inputs to theprocess chamber 172 and the fluid distribution system 174 as well asmonitor outputs from these systems. A program stored in the memory isutilized to interact with the systems 172 and 174 according to a storedprocess recipe. One example of controller 176 is a DELL PRECISIONWORKSTATION 530™, available from Dell Corporation, Austin, Tex. Thecontroller 176 may also be implemented as a general purpose computer,digital signal process, etc.

Controller 176 may be locally located relative to the process chamber172 and the fluid distribution system 174, or it may be remotely locatedrelative to the process chamber 172 and the fluid distribution system174 via an internet or intranet. Thus, controller 176 can exchange datawith the process chamber 172 and the fluid distribution system 174 usingat least one of a direct connection, an intranet, and the internet.Controller 176 may be coupled to an intranet at a customer site (i.e., adevice maker, etc.), or coupled to an intranet at a vendor site (i.e.,an equipment manufacturer). Furthermore, another computer (i.e.,controller, server, etc.) can access controller 176 to exchange data viaat least one of a direct connection, an intranet, and the internet.

FIG. 6 shows a simplified schematic of a supercritical processingapparatus 200. The apparatus 200 includes a carbon dioxide source 221that is connected to an inlet line 226 through a source valve 223 whichcan be opened and closed to start and stop the flow of carbon dioxidefrom the carbon dioxide source 221 to the inlet line 226. The inlet line226 is preferably equipped with one or more back-flow valves, pumps, andheaters, schematically shown by the box 220, for generating and/ormaintaining a stream of supercritical carbon dioxide. The inlet line 226also preferably has an inlet valve 225 that is configured to open andclose to allow or prevent the stream of supercritical carbon dioxidefrom flowing into a processing chamber 201.

Still referring to FIG. 6, the processing chamber 201 is preferablyequipped with one or more pressure valves 209 for exhausting theprocessing chamber 201 and/or for regulating the pressure within theprocessing chamber 201. Also, the processing chamber 201, in accordancewith the embodiments of the invention, is coupled to a pump and/or avacuum 211 for pressurizing and/or evacuating the processing chamber201.

Again referring to FIG. 6, within the processing chamber 201 of theapparatus 200 there is preferably a chuck 233 for holding and/orsupporting a wafer structure 213. The chuck 233 and/or the processingchamber 201, in accordance with further the embodiments of theinvention, has one or more heaters 231 for regulating the temperature ofthe wafer structure 213 and/or the temperature of a supercriticalprocessing solution within the processing chamber 201.

The apparatus 200, also preferably has a circulation line or loop 203that is coupled to the processing chamber 201. The circulation line 203is preferably equipped with one or more valves 215 and 215′ forregulating the flow of a supercritical processing solution through thecirculation line 203 and through the processing chamber 201. Thecirculation line 203 is also preferably equipped with any numberback-flow valves, pumps, and/or heaters, schematically represented bythe box 205, for maintaining a supercritical processing solution andflowing the supercritical processing solution through the circulationline 203 and through the processing chamber 201. In accordance with anembodiment of the invention, the circulation line 203 has an injectionport 207 for introducing chemistry, such as a healing compound, into thecirculation line 203 for generating supercritical processing solutionsin situ.

FIG. 7 shows a supercritical processing apparatus 76 in more detail thanFIG. 6 described above. The supercritical processing apparatus 76 isconfigured for generating and for treating a wafer with supercriticaltreating solutions. The supercritical processing apparatus 76 includes acarbon dioxide supply vessel 332, a carbon dioxide pump 334, theprocessing chamber 336, a chemical supply vessel 338, a circulation pump340, and an exhaust gas collection vessel 344. The carbon dioxide supplyvessel 332 is coupled to the processing chamber 336 via the carbondioxide pump 334 and carbon dioxide piping 346. The carbon dioxidepiping 346 includes a carbon dioxide heater 348 located between thecarbon dioxide pump 334 and the processing chamber 336. The processingchamber 336 includes a processing chamber heater 350.

The circulation pump 340 is located on a circulation line 352, whichcouples to the processing chamber 336 at a circulation inlet 354 and ata circulation outlet 356. The chemical supply vessel 338 is coupled tothe circulation line 352 via a chemical supply line 358, which includesa first injection pump 359. A rinse agent supply vessel 360 is coupledto the circulation line 352 via a rinse supply line 362, which includesa second injection pump 363. The exhaust gas collection vessel 344 iscoupled to the processing chamber 336 via exhaust gas piping 364.

The carbon dioxide supply vessel 332, the carbon dioxide pump 334, andthe carbon dioxide heater 348 form a carbon dioxide supply arrangement349. The chemical supply vessel 338, the first injection pump 359, therinse agent supply vessel 360, and the second injection pump 363 form achemical and rinse agent supply arrangement 365.

It will be readily apparent to one skilled in the art that thesupercritical processing apparatus 76 includes valving, controlelectronics, filters, and utility connections that are typical ofsupercritical fluid processing systems.

Still referring to FIG. 7, in operation, a wafer (not shown) with adielectric film thereon is inserted into the wafer cavity 312 of theprocessing chamber 336 and the processing chamber 336 is sealed byclosing the gate valve 306. The processing chamber 336 is pressurized bythe carbon dioxide pump 334 with the carbon dioxide from the carbondioxide supply vessel 332 and the carbon dioxide is heated by the carbondioxide heater 348 while the processing chamber 336 is heated by theprocessing chamber heater 350 to ensure that a temperature of the carbondioxide in the processing chamber 336 is above a critical temperature.The critical temperature for the carbon dioxide is 31 C. Preferably, thetemperature of the carbon dioxide in the processing chamber 336 iswithin a range of range of from 40 C to about 200 C, and preferably ator near to 150 C, during a supercritical passivating step.

Upon reaching initial supercritical conditions, the first injection pump359 pumps the processing chemistry, such as a healing compound, from thechemical supply vessel 338 into the processing chamber 336 via thecirculation line 352 while the carbon dioxide pump further pressurizesthe supercritical carbon dioxide. At the beginning of the addition ofprocessing chemistry to the processing chamber 336, the pressure in theprocessing chamber 336 is preferably about 1,070 to 9,000 psi andpreferably at or near 3,000 psi. Once a desired amount of the processingchemistry has been pumped into the processing chamber 336 and desiredsupercritical conditions are reached, the carbon dioxide pump 334 stopspressurizing the processing chamber 336, the first injection pump 359stops pumping processing chemistry into the processing chamber 336, andthe circulation pump 340 begins circulating the supercritical cleaningsolution including the supercritical carbon dioxide and the processingchemistry. Preferably, the pressure within the processing chamber 336 atthis point is about 3000 psi. By circulating the supercriticalprocessing solution, supercritical processing solution is replenishedquickly at the surface of the wafer thereby enhancing the rate ofpassivating the surface of the dielectric layer on the wafer.

When a wafer (not shown) with a dielectric layer is being processedwithin the pressure chamber 336, the wafer is held using a mechanicalchuck, a vacuum chuck or other suitable holding or securing means. Inaccordance with the embodiments of the invention the wafer is stationarywithin the processing chamber 336 or, alternatively, is rotated, spun orotherwise agitated during the supercritical process step.

After the supercritical processing solution is circulated thoughcirculation line 352 and the processing chamber 336, the processingchamber 336 is partially depressurized by exhausting some of thesupercritical process solution to the exhaust gas collection vessel 344in order to return conditions in the processing chamber 336 to near theinitial supercritical conditions. Preferably, the processing chamber 336is cycled through at least one such decompression and compression cyclebefore the supercritical processing solutions are completely exhaustedfrom the processing chamber 336 to the collection vessel 344. Afterexhausting the pressure chamber 336, a second supercritical process stepis performed, or the wafer is removed from the processing chamber 336through the gate valve 306, and wafer processing is continued in asecond processing apparatus or module (not shown).

FIG. 8 illustrates an exemplary plot 400 of pressure versus time for asupercritical process step, such as a supercritical cleaning/passivatingprocess step, in accordance with the method of the present invention.Now referring to both FIGS. 7 and 8, prior to an initial time T₀, thewafer structure with post-etch residue thereon is placed within theprocessing chamber 336 through the gate valve 306 and the processingchamber 336 is sealed. From the initial time T₀ through a first durationof time T₁, the processing chamber 336 is pressurized. When theprocessing chamber 336 reached critical pressure P_(c)(1,070 psi), thena processing chemistry including a healing compound is injected into theprocessing chamber 236, preferably through the circulation line 352, asexplained previously. The processing chemistry preferably includeshexamethyldisilazane (HMDS), chlorotrimethylsilane (TMCS),trichloromethylsilane (TCMS) and combinations thereof which are injectedinto the system. Several injections of process chemistries can beperformed over the duration of time T₁ to generate a supercriticalprocessing solution with the desired concentrations of chemicals. Theprocessing chemistry, in accordance with the embodiments of theinvention, can also include one more or more carrier solvents, amminesalts, hydrogen fluoride and/or other sources of fluoride, orN,N-dimethylacetamide (DMAC), gamma-butyrolacetone (BLO), dimethylsulfoxide (DMSO), ethylene carbonate (EC) N-methylpyrrolidone (NMP),dimethylpiperidone, propylene carbonate, alcohol or combinationsthereof. Preferably, the injection(s) of the process chemistries beginupon reaching about 1100-1200 psi, as indicated by the inflection point405. Alternatively, the processing chemistry is injected into theprocessing chamber 336 around the second time T₂, or after the secondtime T₂.

After processing chamber 336 reaches an operating pressure P_(op) at thesecond time T₂ which is preferably about 3,000 psi (but can be any valueso long as the operating pressure is sufficient to maintainsupercritical conditions), the supercritical processing solution iscirculated over and/or around the wafer and through the processingchamber 336 using the circulation line 325, such as described above.Then the pressure within the processing chamber 336 increases and, overthe next duration of time, the supercritical processing solutioncontinues to be circulated over and/or around the wafer and through theprocessing chamber 336 using the circulation line 325 and/or theconcentration of the supercritical processing solution within theprocessing chamber is adjusted by a push-through process, as describedbelow.

Still referring to FIG. 8, in a push-through process, over the durationof time T₃, a fresh stock of supercritical carbon dioxide is fed intothe processing chamber 336, while the supercritical cleansing solutionalong with process residue suspended or dissolved therein issimultaneously displaced from the processing chamber 336 through thevent line 364. After the push-through step is complete, then over aduration of time T₄, the processing chamber 336 is cycled through aplurality of decompression and compression cycles. Preferably, this isaccomplished by venting the processing chamber 336 below the operatingpressure P_(op) to about 1,100-1,200 psi in a first exhaust and thenraising the pressure within the processing chamber 336 from 1,100-1,200psi to the operating pressure P_(op), or above with a first pressurerecharge. Afterwards, the decompression and compression cycles arecomplete, and the processing chamber is completely vented or exhaustedto atmospheric pressure. For wafer processing, a next wafer processingstep begins or the wafer is removed form the processing chamber andmoved to a second process apparatus or module to continue processing.

The plot 400 is provided for exemplary purposes only. It will beunderstood by those skilled in the art that a supercritical processingstep can have any number of different time/pressures or temperatureprofiles without departing from the scope of the present invention.Further any number of cleaning and rinsing processing sequences witheach step having any number of compression and decompression cycles arecontemplated. Also, as stated previously, concentrations of variouschemicals and species within a supercritical processing solution can bereadily tailored for the application at hand and altered at any timewithin a supercritical processing step. In accordance with the preferredembodiment of the invention, a dielectric layer is treated to 1 to 10passivation steps in approximately 3 minute cycles, as described abovewith reference to FIGS. 6 and 7.

FIG. 9 is a block diagram 500 outlining steps for treating a substratestructure including a patterned low-k dielectric layer and post-etchresidue thereon using a supercritical cleaning and a treating compound(or passivating solution). In the step 502, the substrate structureincluding the post-etch residue is placed and sealed within a processingchamber. After the substrate structure is placed into and sealed withinprocessing chamber in the step 502, in the step 504 the processingchamber is pressurized with supercritical CO₂ and processing chemistryis added to the supercritical CO₂ to generate a supercritical cleaningand passivating solution. Preferably, the cleaning and passivatingchemistry includes at least one organosilicon compound.

After the supercritical cleaning and passivating solution is generatedin the step 504, in the step 506 the substrate structure is maintainedin the supercritical processing solution for a period of time sufficientto remove at least a portion of the residue from the substrate structureand passivate surfaces exposed after the residue is removed. During thestep 506, the supercritical cleaning and passivating solution ispreferably circulated through the processing chamber and/or otherwiseagitated to move the supercritical cleaning solution over surfaces ofthe substrate structure.

Still referring to FIG. 9, after at least a portion of the residue isremoved from the substrate structure in the step 506, the processingchamber is partially exhausted in the step 508. The cleaning processincluding steps 504 and 506 are repeated any number of times, asindicated by the arrow connecting the steps 508 to 504, required toremove the residue from the substrate structure and passivate thesurfaces exposed. The processing including steps 504 and 506, inaccordance with the embodiments of the invention, using freshsupercritical carbon dioxide, fresh chemistry or both. Alternatively,the concentration of the cleaning chemistry is modified by diluting theprocessing chamber with supercritical carbon dioxide, by addingadditional charges of cleaning chemistry or a combination thereof.

Still referring to FIG. 9, after the processing steps 504, 506, and 508are complete, in the step 510 the substrate structure is preferablytreated to a supercritical rinse solution. The supercritical rinsesolution preferably includes supercritical CO₂ and one or more organicsolvents, but can be pure supercritical CO₂.

Still referring to FIG. 9, after the substrate structure is cleaned inthe steps 504, 506, and 508 and rinsed in the step 510, in the step 512the processing chamber is depressurized and the substrate structure isremoved from the processing chamber. Alternatively, the substratestructure is cycled through one or more additional cleaning/rinsingprocesses including the steps 504, 506, 508, and 510 as indicated by thearrow connecting steps 510 and 504. Alternatively, or in addition tocycling the substrate structure through one or more additionalcleaning/rinse cycles, the substrate structure is treated to severalrinse cycles prior to removing the substrate structure from the chamberin the step 512, as indicated by the arrow connecting the steps 510 and508.

As described previously, the substrate structure can be dried and/orpretreated prior to passivating the low-k dielectric layer thereon byusing a supercritical solution including supercritical carbon dioxideand one or more solvents such as methanol, ethanol, n-hexane, and/orcombination thereof. Also, as mentioned previously, pre-treating thelow-k dielectric layer with supercritical solution includingsupercritical carbon dioxide and n-hexane appears to improve thecoverage of the silyl-groups on surface of the low-k dielectric layer.Also, it will be clear of one skilled in the art that a wafer includinga post-etch residue and/or a patterned low-k dielectric layer can betreated to any number cleaning and passivating steps and/or sequences.

It will be understood by one skilled in the art, that while the methodof passivating low-k dielectric material has been primarily describedherein with reference to a post-etch treatment and/or a post-etchcleaning treatment, the method of the present invention can be used todirectly passivate low-k dielectric materials. Further, it will beappreciated that when treating a low-k dielectric material, inaccordance with the method of the present invention, a supercriticalrinse step is not always necessary and simply drying the low-kdielectric material prior to treating the low-k dielectric material witha supercritical passivating solution can be appropriate for someapplications.

In one example, a supercritical processing system, such as thatdescribed in detail above in FIGS. 6 and 7, is utilized to processsamples with a low-k dielectric layer formed from MSQ materials byexposing this layer to a healing compound under several conditions.Under a first set of conditions, a sample with a layer of the low-kdielectric material was treated with a solution of hexane andapproximately 6 percent TMCS. The sample was then annealed atapproximately 100 C for approximately one hour. Under a second set ofconditions, a sample with a layer of the low-k dielectric material wastreated with a supercritical carbon dioxide passivating solution withapproximately 1.0 percent TMCS at approximately 3,000 psi. Under yet athird set of conditions, a sample with a layer of the low-k dielectricmaterial was treated with a supercritical carbon dioxide passivatingsolution with approximately 1.0 percent TMCS at approximately 3,000 psiat 100 C. After treatment of the samples under the conditions describedabove, Fourier Transform Infrared (FTIR) spectra of untreated samplesand each of the treated samples were collected. A comparative plot ofthe FTIR spectra collected are shown in FIGS. 10A and 10B.

FIG. 10A plots the (1R) spectral region from a wavenumber ofapproximately 250 to 4,000 (m⁻¹). The peak 611 corresponds to the C—Hstretching of the Si(CH₃)₃ groups, which is considerably increased forall of the samples treated with the treating compound. The peak 661corresponds to C—H bending of the Si(CH₃)₃ groups, which is alsoconsiderably increased for all of the samples treated with the treatingcompound. FIG. 10B shows comparative plots of an expanded region of the(IR) spectra shown in FIG. 10A, from a wavenumber of approximately 2,800to 3,100 in order to more clearly illustrate the increase in the peak661 for the treated samples.

Still referring to FIG. 10A, a broad peak 663 corresponding to O—Hstretching, which is negligible in the treated samples, but ispronounced in the untreated sample. From spectra shown in FIGS. 10A and10B, it is clear that TMCS is an effective treating compound for thepassivation of low-k dielectric material surfaces in both wet benchconditions and under supercritical processing conditions.

The present invention has the capability of passivating a low-kdielectric surface and being compatible with other processing steps,such as removing post-etch residues (including, but not limited to,spin-on polymeric anti-reflective coating layers and photopolymers) forpatterned low-k dielectric layers in a supercritical processingenvironment.

The present invention also has been observed to restore or partiallyrestore the dielectric constant (k −value) of dielectric materials lostafter patterning steps, and has been shown to produce low-k dielectriclayers that are stable over time. The present invention also has beenobserved to seal or partially seal exposed porous surfaces.

Although only certain exemplary embodiments of this invention have beendescribed in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. For example, while damage to the low-ksurface is primarily described with respect to etch or ash createddamage, the present invention is not limited to treating only suchdamage, and may be implemented to treat damage to low-k films caused byother handling or processing of the wafer containing a low-k film.Accordingly, all such modifications are intended to be included withinthe scope of this invention.

1. A method of treating a dielectric film comprising: exposing at leastone surface of said dielectric film to a treating compound comprising analkyl silane, an alkoxysilane, an alkyl siloxane, an alkoxysiloxane, anaryl silane, an acyl silane, a cyclo siloxane, a polysilsesquioxane(PSS), an aryl siloxane, an acyl siloxane, or a halo siloxane, or anycombination thereof, wherein: said dielectric film has a dielectricconstant value less than the dielectric constant of SiO₂.
 2. The methodof claim 1, wherein said treating compound comprises an alkyl silanecomprising: hexamethyldisilazane (HMDS), tetramethyldisilazane (TMDS),trimethylsilyidimethylamine (TMSDMA), trimethylsilyldiethylamine(TMSDEA), N-trimethylsilyl-imidazole (TMSI), methyltrimethoxysilane(MTMOS), vinyltrimethoxysilane (VTMOS), trimethylchlorosilane (TMCS),dimethylsilyidimethylamine (DMSDMA), dimethylsilyldiethylamine (DMSDEA),bis(dimethylamino)methyl silane (B[DMA]MS), bis(dimethylamino)dimethylsilane (B[DMA]DS), dimethylaminopentamethyldisilane (DMAPMDS),dimethylaminodimethyldisilane (DMADMDS), disila-aza-cyclopentane(TDACP), disila-oza-cyclopentane (TDOCP), triethylchlorosilane (TECS),tetramethoxysilane (TMOS), dimethyldimethoxysilane (DMDMOS),tetraethoxysilane (TEOS), methyltriethoxysilane (MTEOS),dimethyldiethoxysilane (DMDEOS), vinyltriethoxysilane (VTEOS),trimethylmethoxysilane (TMMS), trimethylethoxysilane (TMES),trimethylsilanol (TMS-OH), bis(trimethoxysilyl)hexane,bis(trimethoxysilyl)octane, bis(trimethylsilylmethyl)dimethoxysilane,bistrimethoxysilylethane, cyclohexylmethyldimethoxysilane,cyclohexyltrimethoxysilane, dicyclopentyldimethoxysilane,diisobutyldimethoxysilane, diisopropyldimethoxysilane,dimethyldimethoxysilane, hexadecyltrimethoxysilane,octyldimethylmethoxysilane, trimethoxysilane, trimethylmethoxysilane, ortris(dimethylsiloxy)ethoxysilane, or any combination thereof.
 3. Themethod of claim 1, wherein said treating compound comprises an alkylsiloxane comprising: (3-glycidoxypropyl) pentamethyldisiloxane,1,1,1,3,3,5,5-heptamethyltrisiloxane, 1,1,1,5,5,5-hexamethyltrisiloxane,1,1,3,3,5,5,7,7-octamethyltetrasiloxane,1,1,3,3,5,5-hexamethyltrisiloxane,1,1,3,3-tetracyclopentyldichlorodisiloxane,1,1,3,3-tetraethoxy-1,3-dimethyldisiloxane,1,1,3,3-tetraisopropyl-1,3-dichlorodisiloxane,1,1,3,3-tetraisopropyldisiloxane,1,1,3,3-tetramethyl-1,3-diethoxydisiloxane,1,1,3,3-tetramethyldisiloxane,1,3-bis(2-aminoethylaminomethyl)tetramethyldisiloxane,1,3-bis(3-aminopropyl)tetramethyldisiloxane,1,3-bis(chloromethyl)-1,1,3,3-tetrakis(trimethylsiloxy)disiloxane,1,3-bis(chloropropyl)tetramethyldisiloxane,1,3-bis(glycidoxypropyl)tetramethyld isiloxane,1,3-bis(hydroxybutyl)tetramethyldisiloxane,1,3-bis(hydroxypropyl)tetramethyldisiloxane,1,3-bis(trimethylsiloxy)-1,3-dimethyldisiloxane,1,3-diallyleterakis(trimethylsiloxy)disiloxane,1,3-diallyltetramethyldisiloxane, 1,3-dichlorotetramethyldisiloxane,1,3-diethyltetramethyldisiloxane, 1,3-diethynyltetramethyldisiloxane,1,3-dimethyltetramethoxydisiloxane, 1,3-dioctyltetramethyldisiloxane,1,3-divinyl-1,3-dimethyl-1,3-dichlorodisiloxane,1,3-divinyltetraethoxydisiloxane, 1,3-divinyltetramethyldisiloxane,1,5-d ichlorohexamethyltrisiloxane, 1,5-divinylhexamethyltrisiloxane,1,7-d ichlorooctamethyltetrasiloxane,1-allyl-1,1,3,3-tetramethyldisiloxane,2-[methoxy(polyethyleneoxy)propyl]heptamethyltrisiloxane,3,5-bis(chloromethyl)octamethyltetrasiloxane,3-[hydroxy(polyethyleneoxy)propyl]heptamethyltrisiloxane,3-aminopropylpentamethyldisiloxane,3-chloromethylheptamethyltrisiloxane, 3-octylheptamethyltrisiloxane,bis(3-chloroisobutyl)tetramethyldisiloxane,bis(chloromethyl)tetramethyldisiloxane,bis(cyanopropyl)tetramethyldisiloxane,bis(tridecafluoro-1,1,2,2-tetrahydrooctyl)tetramethyldisiloxane,bis(trifluoropropyl)tetramethyldisiloxane,bis[(biscycloheptenyl)ethyl]tetramethyldisiloxane,bis-2-[3,4-(epoxycylcohexyl)ethyl]tetramethyldisiloxane,chloromethylpentamethyldisiloxane, decamethylcyclopentasiloxane,decamethyltetrasiloxane, divinyletrakis(trimethylsiloxy)disiloxane,dodecamethylcyclohexasiloxane, dodecamethylpentasiloxane,hexaethyldisiloxane, hexamethyldisiloxane, hexavinyldisiloxane,octamethyltrisiloxane, pentamethyldisiloxane, ortetradecamethylhexasiloxane, or any combination thereof.
 4. The methodof claim 1, wherein said treating compound comprises an aryl silanecomprising: benzyltriethoxysilane, di(p-tolyl)dimethoxysilane,diphenyldiethoxysilane, diphenyldihydroxysilane,diphenyldimethoxysilane, diphenylmethylethoxysilane,p-bis(trimethoxysilylmethyl)benzene, phenyldimethylethoxysilane,t-butyldiphenylmethoxysilane, triphenylethoxysilane, triphenylsilanol,vinyidiphenylethoxysilane, dibenzyloxydiacetoxysilane,phenylacetoxytrimethylsilane, phenyldimethylacetoxysilane, orphenyltriacetoxysilane, or any combination thereof.
 5. The method ofclaim 1, wherein said treating compound comprises an acyl silanecomprising: bistrimethylsilyl urea (BTSU), bis(trimethylsilyl)acetamide(BSA), bis(trimethylsilyl)trifluoromethylacetamide (BSTFA),triacetylvinylsilane (TAVS),N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA),N-methyl-N-tert-butyldimethylsilyl-trifluoroacetamide (MBDSTFA),N-methyl-N-trimethylsilyl-heptafluorobutyramide (MSHFBA),acetoxytrimethylsilane (TMAS), 3-trifluoroacetoxypropyltrimethoxysilane,acetoxyethyldimethylchlorosilane, acetoxyethylmethyldichlorosilane,acetoxyethyltriclorosilane, acetoxyethyltriethoxysilane,acetoxyethyltrimethoxysilane, acetoxymethyldimethylacetoxysilane,acetoxymethyltriethoxysilane, acetoxymethyltrimethoxysilane,acetoxymethyltrimethylsilane, acetoxypropylmethyldichlorosilane,dimethyldiacetoxysilane, di-t-butyldiacetoxysilane,ethyltriacetoxysilane, methyltriacetoxysilane, tetraacetoxysilane,tetrakis(trifluoroacetoxy)silane, triethylacetoxysilane,vinylmethyldiacetoxysilane, vinyltriacetoxysilane,dibenzyloxydiacetoxysilane, phenylacetoxytrimethylsilane,phenyldimethylacetoxysilane, or phenyltriacetoxysilane, or anycombination thereof.
 6. The method of claim 1, wherein said treatingcompound comprises an cyclo siloxane comprising:1,3,5,7-tetramethylcyclotetrasiloxane, heptamethylcyclotetrasiloxane,hexaethylcyclotrisiloxane, hexamethylcyclotrisiloxane,octamethylcyclotetrasiloxane, pentamethylcyclopentasiloxane,pentavinylpentamethylcyclopentasiloxane, tetraethylcyclotetrasiloxane,hexaphenylcyclotrisiloxane, octaphenylcyclotetrasiloxane,(acetoxyethyl)heptamethylcylcotetrasiloxane, ortetrakis(diphenylphosphinoethyl)tetramethylcylcotetrasiloxane, or anycombination thereof.
 7. The method of claim 1, wherein said treatingcompound comprises an aryl siloxane comprising:1,1,3,3-tetraphenyldimethyldisifoxane,1,1,3,5,5-pentaphenyl-1,3,5-trimethyltrisiloxane,1,1,5,5-tetraphenyl-1,3,3,5-tetramethyltrisiloxane,1,3-dichloro-1,3-diphenyl-1,3-dimethyldisiloxane,1,3-dichlorotetraphenyldisiloxane,1,3-diphenyl-1,1,3,3-tetrakis(dimethylsiloxy)disiloxane,1,3-diphenyl-1,1,3,3-tetramethyldisiloxane,1,3-divinyl-1,3-diphenyl-1,3-dimethyldisiloxane,1,4-bis(trimethoxysilylethyl)benzene,1,5-bis(glycidoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane,1,5-divinyl-3,3-diphenyl-1,1,5,5-tetramethyltrisiloxane,1,5-divinyl-3-phenylpentamethyltrisiloxane,3,5-diphenyloctamethyltetrasiloxane,3-phenyl-1,1,3,5,5-pentamethyltrisiloxane,3-phenylheptamethyltrisiloxane,bis(m-allylphenyldimethylsilyloctyl)-tetramethyldisiloxane,bis(pentafluorophenyldimethoxysilane, divinyltetraphenyldisiloxane,hexaphenyldisiloxane, hexaphenylcyclotrisiloxane,1,3-bis[acrylomethyl)phenethyl]tetramethyldisiloxane,octaphenylcyclotetrasiloxane,(acetoxyethyl)heptamethylcylcotetrasiloxane, ortetrakis(diphenylphosphinoethyl)tetramethylcylcotetrasiloxane, or anycombination thereof.
 8. The method of claim 1, wherein said treatingcompound comprises an acyl siloxane comprising:1,1,1,3,3-pentamethyl-3-acetoxydisiloxane,1,3-bis(3-carboxypropyl)tetramethyldisiloxane,1,3-bis(3-methacryloxypropyl)tetrakis(trimethylsiloxy)disiloxane,1,3-bis(3-methacryloxypropyl)tetramethyldisiloxane,11-acetoxyundecyltrichlorosilane,2-[acetoxy(polyethyleneoxy)propyl]heptamethyltrisiloxane,methacryloxypropylpentamethyldisiloxane, or1,3-bis[acrylomethyl)phenethyl]tetramethyldisiloxane, or any combinationthereof.
 9. The method of claim 1, wherein said treating compoundcomprises an halo siloxane comprising: hexachlorodisiloxane, oroctachlorotrisiloxane, or any combination thereof.
 10. The method ofclaim 1, wherein said treating compound comprises a polysilsesquioxane(PSS) comprising: octamethyl silsesquioxane, decamethyl siisesquioxane,octavinyl silsesquioxane, decavinyl silsesquioxane, octamethoxysilsesquioxane, decamethoxy silsesquioxane, or chloropropylisobutyl-PSS,or any combination thereof.
 11. The method of claim 1, furthercomprising: exposing said at least one surface of said dielectric filmto at least one of a nitrogen containing material and a chlorinecontaining material.
 12. The method of claim 1, wherein said exposingsaid dielectric film comprises exposing a dielectric film having adielectric constant ranging from 1.6 to 2.7.
 13. The method of claim 1,wherein said exposing said dielectric film comprises exposing at leastone of a porous dielectric film, and a non-porous dielectric film. 14.The method of claim 1, wherein said exposing said porous dielectric filmcomprises exposing at least one of a single-phase material, and adual-phase material.
 15. The method of claim 1, wherein said exposingsaid dielectric film comprises exposing a film including at least one ofan organic material, and an inorganic material.
 16. The method of claim15, wherein said exposing a film comprises exposing a film including aninorganic-organic hybrid material.
 17. The method of claim 15, whereinsaid exposing a film comprises exposing a film including an oxidizedorgano silane.
 18. The method of claim 15, wherein said exposing a filmcomprises exposing a film including at least one of hydrogensilsesquioxane, and methyl silsesquioxane.
 19. The method of claim 15,wherein said exposing a film comprises exposing a film including asilicate-based material.
 20. The method of claim 15, wherein saidexposing a film comprises exposing a collective film including silicon,carbon, and oxygen.
 21. The method of claim 20, wherein said exposing acollective film further comprises exposing hydrogen in said collectivefilm.
 22. The method of any one of claims 1-10, wherein said exposingsaid dielectric film to said treating compound comprises introducingsaid treating compound in at least one of vapor phase, liquid phase, andwithin a supercritical fluid.
 23. The method of claim 22, wherein saidintroducing said treating compound within said supercritical fluidcomprises introducing said treating compound within supercritical carbondioxide.
 24. The method of claim 1, further comprising: heating saiddielectric film on said substrate to a temperature ranging from 50 C to400 C.
 25. The method of claim 1, wherein exposing said dielectric filmto said treating compound facilitates at least one of healing saiddielectric film, sealing said dielectric film, and cleaning saiddielectric film.
 26. A processing system for treating a dielectric filmon a substrate comprising: a process chamber; a fluid distributionsystem coupled to said process chamber and configured to supply atreating compound to said process chamber in order to treat saiddielectric film on said substrate, said treating compound comprises analkyl silane, an alkoxysilane, an alkyl siloxane, an alkoxysiloxane, anaryl silane, an acyl silane, a cyclo siloxane, a polysilsesquioxane(PSS), an aryl siloxane, an acyl siloxane, or a halo siloxane, or anycombination thereof.
 27. The system of claim 26, wherein said treatingcompound further comprises at least one of a N-containing material and aCl-containing material.
 28. The system of claims 26 or 27, wherein saidtreating compound facilitates at least one of healing said dielectricfilm, sealing said dielectric film, and cleaning said dielectric film.29. The processing system of claim 26, wherein said process chamberfurther comprises a substrate holder configured to support saidsubstrate.
 30. The processing system of claim 29, wherein said substrateholder is further configured to heat said substrate to a temperatureranging from 50 C to 400 C.
 31. The processing system of claim 26,wherein said process chamber comprises a supercritical processingchamber, and said fluid distribution system is configured to supply saidprocess chamber with a supercritical fluid and said treating compound.32. The processing system of claim 26, wherein said process chambercomprises a vapor treatment processing chamber, and said fluiddistribution system is configured to supply a vapor of said treatingcompound to said process chamber.
 33. The processing system of claim 26,wherein said process chamber comprises an immersion bath, and said fluiddistribution system is configured to supply a liquefied treatingcompound to said process chamber.
 34. The processing system of claim 26,wherein said process chamber comprises a liquid-phase treatment system,and said fluid distribution system is configured to dispense saidtreating compound on said dielectric film.
 35. The processing system ofclaim 34, wherein said liquid-phase treatment system comprises asubstrate holder configured to support and rotate said substrate withsaid dielectric film during said dispensing of said treating compound.36. A semiconductor device comprising: a semiconductor substrate; alow-k dielectric film formed on said semiconductor substrate; and meansfor providing at least one of sealing or healing the low-k dielectricfilm, said means located in a surface region of the low-k dielectricfilm.